Field of the Invention
The present invention relates to novel subtilisin variants exhibiting alterations relative to the parent subtilisin in one or more properties including: wash performance, thermal stability, storage stability or catalytic activity. The variants of the invention are suitable for use in e.g. cleaning or detergent compositions, such as laundry detergent compositions and dish wash compositions, including automatic dish wash compositions. The present invention also relates to isolated DNA sequences encoding the variants, expression vectors, host cells, and methods for producing and using the variants of the invention.
Description of the Related Art
In the detergent industry, enzymes have for more than 30 years been implemented in washing formulations. Enzymes used in such formulations comprise proteases, lipases, amylases, cellulases, mannosidases as well as other enzymes or mixtures thereof. Commercially the most important enzymes are proteases.
An increasing number of commercially used proteases are protein engineered variants of naturally occurring wild type proteases, e.g. Everlase®, Relase®, Coronase®, Ovozyme®, Polarzyme®, Liquanase®, Liquanase Ultra® and Kannase® (Novozymes a/s), Maxacal®, Properase®, Purafast®, Purafect OXP®, FN3®, FN4® and Excellase® (DuPont/Genencor International, Inc.) and BLAP (FIG. 29, U.S. Pat. No. 5,352,604) (Henkel AG & Co. KGaA).
Further, a number of variants are described in the art, such as in WO 04/041979 (NOVOZYMES A/S) which describes subtilisin variants exhibiting alterations relative to the parent subtilisin in e.g. wash performance, thermal stability, storage stability or catalytic activity. The variants are suitable for use in e.g. cleaning or detergent compositions.
A number of useful subtilisin variants have been described many of which have provided improved activity, stability, and solubility in different detergents. WO 94/02618 describes subtilisin variants with improved storage stability. The substitutions L211X and N212Z wherein X is any amino acid except L and Z is any amino acid except N are mentioned together with several other mutations. However, no wash performance is shown for these variants and nothing is mentioned in relation to specific stains such as egg stains. It is well known in the art that egg stains are particularly difficult to completely remove and although several protease variants with improved performance on egg stains have been described e.g. in WO 01/44452 there is still a need for proteases which have high wash performance on various stains including egg stains.
It is therefore an object of the present invention to provide variants of a protease with improved properties compared to its parent protease.